Any must-do's?

[SloLearner]

I just got my 2000 400ex about 3 weeks ago and am kinda new to them. I have razrs front and back, a slip-on, and a k&n. I was just wondering if there are any other typical mods that i must do....preferrably cheap and easy ones. Basically i''m looking for things to do before i drop money on suspension.

[Hondabeefast]

ummm....a rev box is an easy mod and you can find them fairly cheap.

[jrm03]

Drop a tooth on the front sprocket

[SloLearner]

any recommendations on brands for the rev box?......and as far as the front sprocket i would rather do something else cause i like the stock gearing.

[Wheelie]

A rev box is a waste of money, IMO, unless the engine is built to take advantage of the extra RPM. The stock rev limiter is 9100rpm, a internally stock 400ex quits making power around 7000rpm.

Open up the air box if you haven't already and re-jet accordingly. Removing the choke will make a noticable difference as well.

[troutman561]

handlebars are good, nerf bars are also a smart thing to get if you already dont have them... and on the rev box, stay away from whitebros. I forget the good brands but im sure someone will chime in and tell soon enough...

[SloLearner]

removing the choke? how does this help performance? and how do i know if i need to jet my bike? i bought it with the pipe and intake and the airbox cover is on but a big hole cut out. is there just a basic guide of mods vs. jets or what?

[Wheelie]

Removing the choke improves throttle response and power. Do a search on the subject, it's been covered extensively.

IMO--Most people over-jet their machines. W/a pipe/filter/modded lid, I would recommend a 40 pilot/155main from sea level to 3000ft.

[jrm03]

The articles section will answer your questions on jetting and checking it properly with your plug, as well as a lot of other threads. The choke removal gave it a bit more response and it costs no money, just up your pilot if you do so.

[81 clark racing]

ya dont get a rev box its a waste of money if you have a stock motor. but if you want to get it then go ahead but dont get whitebros or big gun. good ones are dynatek and gt thunder. those are the only two ive had good luck with.

[jordan_m6]

I dont know why you guys dont like the CDI on a stock motor.
I can understand if you just get a rev box but if you get a CDI it is a good buy.

[2004exrider]

Im pretty sure a rev box and cdi are the same thing. The next thing you can do is get a cam, i was pretty satisfied with my HotCams stage 1.

Jimmy

[drsnugfit]

definately do the choke removal, I have just done it and am well pleased with the result.

a rev box will make the bike extremely hard to start, so hard i killed 2 batteries in one day!

skid plates are always a good start and have the rear shock revalved with an aftermarket link such as the one gt thunder sells...that will make a big big difference in the way the bike handles and make you much faster...

[Kaleigh]

rebox, remove choke, re-jet, pilot jet(only if you have a hard time starting cold), its fine to put a revbox on a stock motor.. it doesnt just change the RPM limit but it changes the Icurve as well.. my engine seems like there less stress on it with the revbox..

[jordan_m6]

Originally posted by 2004exrider
Im pretty sure a rev box and cdi are the same thing. The next thing you can do is get a cam, i was pretty satisfied with my HotCams stage 1.

Jimmy

well they used to make boxes that just added more RPMs but i guess they dont sell those any more. My CDI adds 1100 RPMS and tweeks the spark curve, when i bought mine there was one that just added 800 RPMs. I know they are both CDIs but i call the ones that just add Rs a rev box

[bansheemorphine]

you can make a new airbox out of metal and put your batterie in there too so it's not out in the way on the side of the subframe

[2004exrider]

Originally posted by jordan_m6
well they used to make boxes that just added more RPMs but i guess they dont sell those any more. My CDI adds 1100 RPMS and tweeks the spark curve, when i bought mine there was one that just added 800 RPMs. I know they are both CDIs but i call the ones that just add Rs a rev box

Pretty interesting i didnt know that. Thank you for settling that!:)

Jimmy

[400exMO]

Handlebars, nerfs, pb-blockoff, tether switch. Those are my essentials.

[Honda4lyphe]

what kind of pipe do you have? some pipes will get by without jetting but its best to go ahead and do it (wont hurt anything though)

my main things would be handle bars because the stock bend easy and also nerfs, for starters since you have some good mods on it already. as for suspension..look into the 450r shocks its alot cheaper and easy to do if you have the right tools, plus costs 100 bucks tops usually (on ebay atleast)

[SloLearner]

Thanks for the tips so far guys. I actually do have nerfs btw but the mounts are both broke at the peg. I am assuming i can just reweld it but i'm not sure the material its made out of so anyways....speedysquad what's this about the rear shock? and what is a pb blockoff and tether switch?

[bansheemorphine]

a pb (parking brake) blockoff is just something that goes on the side of your rear caliper replacing the parking brake and a tether switch is some that you hook onto yourself so if u fall off the qaud will shut off it is required for racing and is a good safety thing to have

[Choppers]

My brackets broke also. I just rewelded them together and repainted. The owner before me have the same problem they broke 1 side. The other side broke when i got them. Needless to say the owner before me couldn't weld so i have to redo both.

[christophere251]

dynatec is a good cdi actually gives u more hp from changing the spark timing it bumps the rev limiter up also!

[Honda4lyphe]

Originally posted by SloLearner
Thanks for the tips so far guys. I actually do have nerfs btw but the mounts are both broke at the peg. I am assuming i can just reweld it but i'm not sure the material its made out of so anyways....speedysquad what's this about the rear shock? and what is a pb blockoff and tether switch?

pb blockoff is a good thing..the tether switch is totally optional unless your raceing of course (if you think about it your really not gonna need it) i couldnt find the post on the rear shock but as far as i know the rear shock is really great and can take a real beating, just work on the front ones their fairly good but can always use a upgrade:devil:

this is a problem with the 400ex and 450r...

the stock linkage on these two bikes sets the travel of the shock too high in the chassis, thus making the rear end kick up very harsh when you hit a sharp object or come up just a hair short on a jump where the rear tires just clip the down side of the landing and you end up going over the bars. To solve this you can either raise the top shock mount on the frame by cutting and rewelding it or buy the GT Thunder linkage.

Because this linkage is repositioning the lower shock mount location it is changing the leverage ratio. When you change the leverage ratio at anytime your shock needs to be revalved. On the plus side, your shock will then be valved for YOUR specific weight, riding style, and application(MX, XC, or Recreation). And not for just the "average" rider like it was set at the factory. I will revalve both the compression and rebound shims according to your specific specifications.

derisi also does this modification...

[flauge]

Originally posted by speedyquad
this is a problem with the 400ex and 450r...

the stock linkage on these two bikes sets the travel of the shock too high in the chassis, thus making the rear end kick up very harsh when you hit a sharp object or come up just a hair short on a jump where the rear tires just clip the down side of the landing and you end up going over the bars. To solve this you can either raise the top shock mount on the frame by cutting and rewelding it or buy the GT Thunder linkage.

Because this linkage is repositioning the lower shock mount location it is changing the leverage ratio. When you change the leverage ratio at anytime your shock needs to be revalved. On the plus side, your shock will then be valved for YOUR specific weight, riding style, and application(MX, XC, or Recreation). And not for just the "average" rider like it was set at the factory. I will revalve both the compression and rebound shims according to your specific specifications.

derisi also does this modification... This oughta be at the top of the must do list if you like riding fast. It'll take out like 98% of the bucking. I just got the link right now (thanks zrpilot:D ) without even doing the revalve and it made a night and day difference. I know with the revalve it'll be even better. :cool:

[zrpilot]

Originally posted by flauge
This oughta be at the top of the must do list if you like riding fast. It'll take out like 98% of the bucking. I just got the link right now (thanks zrpilot:D ) without even doing the revalve and it made a night and day difference. I know with the revalve it'll be even better. :cool:


Always happy to help another EX'er enjoy the ride!!!:D